package com.team.gateway.config.gateway;

import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.BlockRequestHandler;
import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.GatewayCallbackManager;
import com.alibaba.csp.sentinel.adapter.gateway.sc.exception.SentinelGatewayBlockExceptionHandler;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.ServerResponse;
import org.springframework.web.reactive.result.view.ViewResolver;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import javax.annotation.PostConstruct;
import java.util.*;

//限流配置 主要是为了配置限流处理器
@Configuration
public class GatewayConfiguration {
    private final List<ViewResolver> viewResolvers;
    private final ServerCodecConfigurer serverCodecConfigurer;

    public GatewayConfiguration(ObjectProvider<List<ViewResolver>> viewResolversProvider,
                                ServerCodecConfigurer serverCodecConfigurer) {
        this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
        this.serverCodecConfigurer = serverCodecConfigurer;
    }

    //配置流控异常处理器
    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {
        return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);
    }

    /**
     * 自定义限流处理器
     */
    @PostConstruct
    public void initBlockHandlers() {
        BlockRequestHandler blockHandler = new BlockRequestHandler() {
            public Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) {
                Map map = new HashMap();
                map.put("code",001);
                map.put("message","不好意思,限流啦");
                return ServerResponse.status(HttpStatus.OK)
                        .contentType(MediaType.APPLICATION_JSON_UTF8)
                        .body(BodyInserters.fromObject(map));
            }
        };
        GatewayCallbackManager.setBlockHandler(blockHandler);
    }

    //引入spring-cloud-starter-alibaba-sentinel依赖限流规则会失效，但可以通过sentinel服务端进行配置
//    //限流全局过滤器
//    @Bean
//    @Order(Ordered.HIGHEST_PRECEDENCE)
//    public GlobalFilter sentinelGatewayFilter() {
//        return new SentinelGatewayFilter();
//    }



//    @PostConstruct
//    public void doInit() {
//        initGatewayRules();
//    }

//    /**
//     * 配置限流规则
//     */
//    private void initGatewayRules() {
//        Set<GatewayFlowRule> rules = new HashSet<>();
//        rules.add(new GatewayFlowRule("auth-service") //路由id
//                .setCount(1) // 限流阈值
//                .setIntervalSec(1) // 统计时间窗口，单位是秒，默认是 1 秒
//        );
//        GatewayRuleManager.loadRules(rules);
//    }

    /**
     * 自定义API限流分组
     *      1.定义分组
     *      2.采用类似initGatewayRules()方式配置限流规则，构建对象是使用API分组的id
     */
//    @PostConstruct
//    private void initCustomizedApis() {
//        Set<ApiDefinition> definitions = new HashSet<>();
//        ApiDefinition api1 = new ApiDefinition("product_api")
//                .setPredicateItems(new HashSet<ApiPredicateItem>() {{
//                    add(new ApiPathPredicateItem().setPattern("/product-service/product/**"). //已/product-service/product/开都的所有url
//                            setMatchStrategy(SentinelGatewayConstants.URL_MATCH_STRATEGY_PREFIX));//匹配策略
//                }});
//        ApiDefinition api2 = new ApiDefinition("order_api")
//                .setPredicateItems(new HashSet<ApiPredicateItem>() {{
//                    add(new ApiPathPredicateItem().setPattern("/order-service/order")); //完全匹配/order-service/order 的url
//                }});
//        definitions.add(api1);
//        definitions.add(api2);
//        GatewayApiDefinitionManager.loadApiDefinitions(definitions);
//    }
//

}
